1. Field of the Invention
This invention pertains to a severing and stripping mechanism for a cable-processing machine, wherein the mechanism includes at least one knife pair whose knives are secured, via knife retainers, on the actuation members of a knife drive and provided with offtake drives, via which the cable ends, after the severing of the cable, are displaced for stripping purposes.
2. Discussion of the Background of the Invention and Material Information
European patent application EP-A 0,509,192, discloses a mechanism with which an electrical cable can be severed with a minimal expenditure of time and stripped to different lengths, without requiring a change of the severing and stripping tools during changes of the stripping length and/or the cross section of the cable. For this purpose, two stripping knives are arranged in each of two knife retainers in a predetermined, fixed distance from a severing knife. The stripping knives, relative to the severing knives, are reduced in length for a such predetermined amount that, during a first part of the working stroke of a knife drive, only the cable is severed. Thereafter, an offtake drive pulls the cable ends back from the place of severing for the desired stripping length, whereupon, during a second part of the working stroke of the knife drive, the insulation is cut. During a further return movement of the cable ends, caused by the offtake drive, the insulation scrap is pulled off while the stripping knives are closed. This mechanism utilizes a relatively complicated knife drive that is arranged underneath the working area so that, in spite of seals, dirt and insulation particles advance up to the gear wheels of the knife drive and cause problems during extended operation thereof. In addition, with this mechanism only those stripping lengths can be achieved that lie within the predetermined, fixed distance of the previously-described knife arrangement.
A printed product sheet of the Japanese company, Shin Meiwa Industry Co. Ltd., located at 2-43, Shitte 3-chome, Tsurumi-ku, Yokohama 230, Japan, describes a severing and stripping mechanism which includes a knife pair that includes several cutting edges on each knife. During operation, there occurs, as usual, the severing of the cable with the multi-cutting edge knife after the length-wise transport of the cable. After the knife opening, the cable handling components move linearly and parallel to the knife, via controlled spindles, to the left and to the right to a stripping place. Thereafter, the handling components, on each side of the knife, with the cut cables, are displaced in the direction of the knife for the required stripping length. This is followed by a knife stroke to the required stripping diameter and the pullback of the insulation remnants or scrap as well as the linear further movement or return movement of the cable depending on the next working step. A disadvantage of this mechanism resides therein that the relatively heavy cable handling component must constantly be displaced in the axial and lateral directions which can lead to greater clock cycles or greater energy usage and wear. In addition, the utilization of multiple edge knives can be economically disadvantageous since it can lead to unequal wear thus requiring the changing thereof even though useable cutting edges remain.
In a similar mechanism, disclosed in European patent publication EP-A-0,499,753, difficulties can occur during the processing of very flexible conductors. Since such conductors, particularly when connecting elements have already been clamped thereto, can droop considerably, they can bump into the knives during the further transporting thereof. In order to prohibit same, cable guides are provided between the knives, thus causing the mechanism to become more complicated and correspondingly more expensive.